ATV Florida Forum

If I put a stroker crank in my engine and a stock bore size high compression piston in it what work needs to be done other than replacing the crank, connecting rod, and piston with the new ones?

Usually when you replace the piston with a new one it's best to have the bore fitted for the piston cause just slapping a new piston in the stock bore isn't a good idea. Ya, it can be done but even though a piston may say it's for a STD (standard) bore size if you mic the piston vs bore it may be off more than the allowed spec. Just get a new piston and go .010 over to make sure it fits nice and tight.  Or what you could do and it may be cheaper is mill the head .010-.020 to increase compression. That way you can still retain stock bore and pistons.  But remember higher compression and you're gonna need higher octane.  -Mark

Ols school, You are still living in the past. The new 4 strokes usually can't be bored. Just putting in a new piston and rings is the norm. If it is bored you have to have it renicklesil coated.

No, I'm living in the 2 stroke world.  ;)  I didn't look at his sig but looked at his s/n and saw the 350 so I assumed he had a shee.  But that's still pretty crappy about just slapping a piston in there and not boring it over. Talk about possible blow by. Although I have seen some older 2 strokes have a nickle bore  (i.e. 86 kdx 80). Pretty stupid idea IMO. What are the benefits of having a nickle bore? Durability, lower temps?  -Mark

The benefit is closer tolorences and transfers the heat better.

?? Closer tolorences = more friction= more heat. When you say transfers heat better do you mean it disapates the heat better. I always though aluminum disapates heat better than any other metal. ???? -Mark

im just looking in to doing it and i just wanted to know if i need to have it honed or if it is just better to bore it 0.20 over and get a high comp piston to fit.

Whoever you will be using to do your machine work should be able to tell you what kind of shape your cylinder is in. If the cylinder is out of round or has any tapper in it, it will need to be bored to square the cylinder up again.

Will you be doing this work to the Raptor 350?

A little advise, dont spend that kind of money on your 350 Raptor. I'm not knocking it, but after all that time and money all you'll have is a fast Raptor 350. It wont keep up with the 400s or 450s. When you are ready for more bike, sell the 350 and move up, I promise you'll be happier and money ahead.

AGREED

see money is my problem i cant affored $3000 outta my pocket to add to the about  $3500 i would get after sellin the raptor 350. If I do this work it would be done A.T.P. becouse there really good at what they do and mike said he could probably get me a deal on motor work and stuff.

you can buy Z400s all day long for 3500 to $4000

Sell the raptor and get a Z400. Listen to Chillen and Chuck

i found in the trader 400ex and z 400s for 2800,3000 and 3500$$$$$$

well if i do buy another bike i wanna get a yfz450. so ill have to just look around.

Now you're talking, remember that ride I took you on? The problem is, even if you get your motor beefed up, your suspension and chassis will then be the limiting factor.

well im lookin into the money factor of it. but i would like to take a spin on a 450 and maybe a z400 first if its possible to find wich one i like better.

I have a Z400 for sale, almost as fast as my yfz

pics and info on the z400 please.